Tobacco foils and methods of making same



2,893,400 C6 Patented July 7, 1959 TOBACCO FOILS AND, METHODS OF MAKING SAME Ernst-Rolf Detert and Willi Bnchh'olz, Lubbecke, Germany, assignors to EduardGerlach G.m.b.H., Lubbecke, Germany, a German company No Drawing. Application December 10, 1957 Serial No. 701,709

Claims priority, application Germany December 13, 1956 Claims. (Cl. 131- 15) The present invention relates to a method of producing tobacco foils to be used as cover leaves for holding together the tobacco of cigars, cigarillos, stogies, and the like, for shaping the same, and possibly also to serve as wrappers thereof.

Such cover leaves or wrappers are usually made of good burning types of tobacco which have such quality either by nature or in which it is attained by a complicated treatment of inferior or domestic tobacco. Such cover leaves or wrappers must also have sufiici'ent strength to resist being torn, must draw well, and have a mild mellow taste and pleasing aroma when glowing.

There have been many previous attempts to make the cover leaves or wrappers of materials other than tobacco. Thus, for example, they have been made of a suitable paper pulp which was dyed to a brown color. However, it was found that the high cellulose content of the paper unfavorably affects the taste of the tobacco enclosed thereby. Therefore, the use of such paper covering was worthwhile only on cheap brands of cigars and the like or during hard times.

There have also been efforts to prepare a paper solely from tobacco fibers. However, these efiorts did not lead to any practical use since the necessary treatment of the tobacco into a paperlike pulp reduced the taste of the final product considerably. Also, a paper with a certain tobacco content in its pulp led to no success since the tobacco could not be provided in such a high proportion as would be necessary to cover up the cellulose taste. It has also been tried to apply pulverized tobacco upon thin layers of paper. However, this method also did not prove successful.

Furthermore, it has been proposed to bind the tobacco by applying water-soluble swelling agents of a cellulose ether base or polysaccharin compounds such as algin acid alkali salts, pectins, and plant gums. The watery swellings of these substances were mixed with finely pulverized tobacco and made into a paste, rolled out into thin foils under a protective layer of wax paper or pressed out through a slot upon a wire screen and then dried by means of air which was preheated to 50 C.

Although the foillike layers which were thus produced had the advantage of a high tobacco content, they are very sensitive to water and can be worked up only on special machines. Also the resistance to tearing is unsatisfactory if, for reasons of taste, the tobacco content is increased to the required proportion of 90%. Although such foils prepared, for example, by means of cellulose glycolate has also been subsequently made less sensitive to moisture by a treatment with bivalent or polyvalent metal salt compounds with ions of such metals as aluminum, calcium, and magnesium, such after treatment is not only very complicated but it also very seriously aifects the ability of the dried material of properly glowing and holding together. Also, the incorporation of inorganic fillers as proposed prior to this invention for improving the mechanical properties of such a synthetic cover leaf or wrapper is inadvisable since it reduces the tobaccocontent and impairs the glowing thereof.

Attempts have also been made to use water-insoluble cellulose derivatives in the form of acetyl cellulose, viscose, or nitrocellulose for producing tobacco-containing foils or cigarette paper. The use of nitrocellulose is prohibitive for medical reasons because the burning thereof results in nitrous gases which cause serious physical damage. Over and above that, however, such substances considerably impair the taste of the tobacco foils.

It is an object of the present invention to produce a tobacco foil which overcomes the above-mentioned disadvantages of the prior art and which is fully satisfactory both in technical respects and as far as its taste is con cerned. According to the present invention, the pulverized tobacco is consolidated by means of highly or completely methylated methyl cellulose of a degree of methylation of at least 1.6 in an anhydrous solvent. The almost completely nonpolar character of this material is of decisive importance for the purposes of the invention. The solvents which are especially suitable are mixtures of low alcohols with highly volatile chlorinated hydrocarbons.

According to the invention, it has surprisingly been found that the application of these specific materials permits the production of a tobacco foil which is fully equivalent to a natural tobacco leaf and has all the favorable properties thereof. Contrary to the watery mixtures, a mucilage prepared from these materials is capable of taking up a very high content of pulverized tobacco. This has an extremely favorable effect even upon the mechanical properties of the foils thus produced. They may be easily worked both by machine and by hand. Furthermore, it is of advantage that no inorganic additions, such as fibrous solidifying agents are required. Although a softening agent, for example, sugar sirup, may be incorporated, it is also not required. Also, any kinds of tobacco flavors may be added.

The production of the foils may be carried out by stretching out a mixture which has been prepared as above described so as to form a layer of a thickness of about 0.5 to 1 mm. on a smooth base which, if desired, may be cooled and may be rigid or flexible and either flat or curved, in the same manner as conventional in the production of other kinds of foil. The solvents may be very quickly expelled and recovered by hot air and by absorption or by any other suitable treatment. The foil will separate from the base without any difliculty, and it is flexible and may be utilized immediately. This fact is especially remarkable since it was found that films made of other cellulose derivatives, for example, ethyl cellulose and acetyl cellulose, will no longer separate from the base when enriched with such a high, but necessary proportion of tobacco.

The following example may serve as an illustration of the required quantities of the various materials needed for producing a tobacco foil according to the invention;

16.5 parts of dried and pulverized leaf tobacco, the main ingredient of which consists of a particle size capable of passing through a screen having to 200 meshesper square centimeter, are inserted into a mucilage consisting of 24 parts of methanol, 58 parts of methylenechloride, and 1.5 parts of highly methylated methyl cellulose. The homogeneous, thickly viscous mass thus obtained is then applied by suitable drawing means upon a smooth surface and passed through a closed hot-air channel. After the solvents, which may be recovered, have evaporated, the foil may be drawn off and cut ready for further use.

After drying, the foil contains 91% of tobacco ingredients and may be worked up into tobacco goods or used as cover leaves or wrappers.

Although our invention has been illustrated and de- I scribed with reference to the preferred embodiments thereof, we wish to have it understood that it is in no way limited to the details of such embodiments or to the specific examples described, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosedour invention, what we claim is:

1. A method of producing tobacco foils, particularly tor use as a covering of cigars and the like, comprising the steps of mixing finely pulverized tobacco with a viscous solution of a cellulose derivative, comprising highly methylated methyl cellulose of a degree of methylation of at least 1.6 and an anhydrous solvent, shaping the pastymixture into foils, and drying the foils.

' 2. A method as defined in claim 1, in which said viscous solution comprises a mixture of methylen chloride and methyl alcohol as a solvent.

3. A method as defined in claim 1, in which the tobacco ingredients are applied in an un swollen condition.

4. A tobacco foil comprising a thin dried sheet of a finely pulverized tobacco bonded with highly methylated methyl cellulose having a degree of methylation of at least 1.6.

5. A method of producing tobacco foils particularly for use as a covering of cigars and the like, comprising the steps of mixing finely pulverized tobacco with a viscous solution of a cellulose derivative, comprising highly methylated methyl cellulose of a degree of methylation of at least 1.6 and an anhydrous solvent, stretching out the mixture on a smooth base, drying the mixture on the base to form a foil and removing the foil from the base.

Great Britain June 20, 1928 Great Britain June 3, 1953 

1. A METHOD OF PRODUCING TOBACCO FOILS, PARTICULARLY FOR USE AS A COVERING OF CIGARS AND THE LIKE, COMPRISING THE STEPS OF MIXING FINELY PULVERIZED TOBACCO WITH A VISCOUS SOLUTION OF A CELLULOSE DERIVATIVE, COMPRISING HIGHLY METHYLATED METHYL CELLULOSE OF A DEGREE OF METHYLATION OF AT LEAST 1.6 AND AN ANHYDROUS SOLVENT, SHAPING THE PASTY MIXTURE INTO FOILS, AND DRYING THE FOILS. 